1. Field of the Invention
This invention relates to an improved automatic printing plate maker such that the camera is adapted selectively to produce a printing plate of two different qualities in terms of the press life of the plate. In one aspect this invention relates to an improved magazine for a plate maker which affords the selectivity of making a plate from one of two different imagable developable printing plate making materials.
2. Description of the Prior Art
Automatic press plate cameras for making a printing plate generally comprise means for holding a web or roll of photographically sensitized sheet material, advancing means for advancing the sheet material to a focal plane, optical components for focusing an image from a copy board on the sheet material, means for exposing the sheet material and removing the exposed sheet material from the focal plane, and means for developing and processing the exposed material to produce the printing plate or press plate. Such machines have been described in the patent literature and sold commercially. One such patent is U.S. Pat. No. 3,045,540, issued July 24, 1962, to Arthur W. Caps et al. These machines have basically been provided to take a specific type of light-sensitive material, expose the same and automatically process the same to produce the press plate. Machines of this sort have been utilized for photographic processing of the light-sensitive sheet material, either by chemical development as in the Caps et al patent or by electrostatic development as is accomplished in machines as disclosed in the following U.S. Pat. Nos. 3,684,366, issued Aug. 15, 1972 to H. C. Hollwedel Jr.; or 3,634,006, issued Jan. 11, 1972 to H. C. Hollwedel Jr., wherein the original image is on microfilm and projected therefrom to the plate material.
The known prior art however does not teach the building of a system which can utilize a common image input, a common exposure plane, and has separate processors and diverter means for directing sheets thereto, to produce two grades of press plates alternatively, as desired by the operator.